Implementing an Intermetatarsal Screw During Lapidus Arthrodesis

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Arthrodesis of the first metatarsocuneiform joint has become a commonly performed procedure for patients with metatarsus primus elevatus, hallux valgus, hypermobility, arthritis of the first tarsometatarsal (TMT) joint, and in revisional hallux abducto valgus surgery.^1–6

Since its first description by Albrecht in 1911 and later popularization by Paul Lapidus, arthrodesis of the first metatarsocuneiform joint has seen a number of variations.^1,2 These variations include isolated first TMT arthrodesis (Kirschner wires, crossing screws, plate fixation, staple fixation), addition of an intercuneiform screw, a screw from the first metatarsal to the intermediate cuneiform, plantar plating, and biplanar plating.^6–9 Each of these variations has allowed the procedure to evolve over time to improve deformity correction, increase stability, decrease recurrence, and reduce the length of non-weight-bearing status.^6–9

The technique discussed in this article includes the addition of an intermetatarsal screw as well as the application of a shear-strain graft to the arthrodesis site. Implementation of an intermetatarsal screw for the Lapidus procedure provides stress shielding across the metatarsal cuneiform, thereby increasing the likelihood of successful union, which can subsequently improve pain and functional outcomes.⁷   

Figure 1

Step-by-Step Technique Pearls

• First, create a dorsomedial incision over the first metatarsocuneiform joint.
• Next, deepen the incision down to bone, taking care to retract or cauterize neurovascular structures.
• Resect the ligaments of and expose the first TMT joint using a rongeur.
• Resect the first metatarsal base articular surface first, as in my experience, it is the most unstable segment of the first TMT.   
• The first metatarsal base resection should be perpendicular to the long axis of the first metatarsal and parallel to the metatarsal base, as the correction takes place at the cuneiform segment.
• Resect the distal articular surface of the medial cuneiform with angulation to correct for the transverse plane component of the hallux valgus deformity.
• Prepare the joint using a high-speed burr and fenestrate with a 2.5-mm drill. It is helpful to note that a placement of a lamina spreader or Hintermann distractor may facilitate good visualization of the joint preparation.
• Then, expose the medial aspect of the second metatarsal, using a high-speed burr and pituitary rongeur to denude the medial cortex.
• Obtain the final corrected position utilizing a few maneuvers. Derotate the hallux out of valgus by hand or with the use of a Steinmann pin. Your thumb can then reduce the first metatarsal in the transverse plane. Finally, dorsiflex the hallux, thereby plantarflexing the first metatarsal for sagittal plane correction. One should note that in this technique, you rotate the hallux, sesamoids, and metatarsal as one unit, with the soft tissue structures of the first MTPJ left intact. It is important to consider that in the author’s training and experience, the sagittal plane component of the hallux valgus deformity often goes overlooked during correction.
• Hold proper position with temporary K-wires. It is important to ensure that there is good bony apposition to the plantar aspect of the first TMT. You can address any gapping noted dorsally with autogenous bone graft at the end of the procedure.
• Create a “Manoli” hole¹⁰ in the dorsal aspect of the first metatarsal for placement of the 3.5mm “home run screw.” It is important that this screw obtain bicortical purchase to the plantar aspect of the proximal medial cuneiform. This provides interfragmentary compression and provides resistance to the ground reactive forces.¹⁰ The author notes that this screw may appear long on the AP radiographic view, but proper placement can be confirmed on a lateral x-ray.
• Apply a locking plate to the medial aspect of the first TMT joint and fixate with a combination of locking and nonlocking screws.
• Typically, one now places 2 lag screws transversely across the medial cuneiform and into the intermediate cuneiform.
• Place the third screw transversely across the first interspace and into the second metatarsal. As coined by DiDomenico, this allows the plate to act as a large washer to aid in reduction of the intermetatarsal angle.¹¹
• If additional stability is needed, drive the screw into the third metatarsal for fixation of additional cortices.
• Typically, you will now place locking screws through the remaining holes.
• Place an autogenous bone graft to act as a shear-strain graft to the dorsal aspect of the fusion site. You can obtain this graft with a stab incision made to the lateral aspect of the calcaneus, then introducing a drill, followed by sequentially larger curettes.
• Use a burr to create a hole at the intercuneiform joint to apply the autogenous bone graft here as well.  
• As with any arthrodesis procedure it is important to be cognizant of the principles of arthrodesis, as technique is critical to achieve bony union and reduce the risk of recurrence (remove soft tissues, prepare bone, drill for bleeding, rigid fixation).

Figure 2

Pointers on the Postoperative Protocol

Patients may immediately ambulate in a controlled ankle motion boot until evidence of radiographic union is noted by visualizing trabeculation across the fusion site and observing clinically evident subsidence of pain and edema.

When fusion is achieved, the patients transition into normal shoe gear and may ambulate to tolerance with the addition of physical therapy.

Figure 3

A Closer Look at the Research on Intermetatarsal Screws

Implementation of an intermetatarsal screw for a Lapidus procedure provides stress shielding across the first TMT, aids and maintains reduction of intermetatarsal angle, and provides an increase in stability. These components improve union across the first TMT joint, which can subsequently improve pain and functional outcomes.⁸

A study by Feilmeier and colleagues supports this principle by reporting a reduction in transverse and coronal plane forces across the first TMT joint due to the application of an intermetatarsal screw across the first and second metatarsal bases.⁹

Jones and colleagues reported a 5% non-union rate in their study and a 0.5 degree angle increase with an addition of an intermetatarsal screw. Additionally, Sangeorzan and Hansen have shown that a transverse screw provides rotational stability allowing for rotational stability.⁷

Additionally, Sangeorzan reported the addition of bone graft and multiple points of fixation provides increased stability directly led to improved patient outcomes.

Final Thoughts

Although there are many benefits to the utilization of an intermetatarsal screw for a Lapidus procedure, many podiatric surgeons are hesitant to implement this step due to the increase in stiffness of the construct as well as the theoretical higher possibility of broken hardware. An unpublished retrospective study—presented at the 2023 American College of Foot and Ankle Surgeons Annual Scientific Conference by DiDomenico, Spingola, Butto, and colleagues—consisted of 222 Lapidus procedures revealing 12 patients with intermetatarsal screw failure (5.4%) and no lesser metatarsal fractures. Secondary findings included 5 non-unions (2.5%) and 2 cases of recurrence (1%).¹⁵ It is my hope that the technique noted above can give the surgeon confidence that the addition of an intermetatarsal screw increases stability across the fusion site allowing for immediate weight-bearing and higher union rate, with a low complication rate.

Dr. Spingola is a fellowship trained foot and ankle surgeon at Oklahoma City Orthopedics Sports & Pain Medicine at Foot and Ankle Surgeons of Oklahoma P.L.L.C.

For further reading, see “Is MIS a Viable Alternative to the Lapidus for Larger Bunions?”, “Instability of the Lisfranc Joint After Lapidus Bunionectomy: A Case Report”, or “Taking A Closer Look At Lapidus Procedure Outcomes.”

References
1.     Albrecht GH. The pathology and treatment of hallux valgus. Russk Vrach. 1910; 10:14–19.
2.     Lapidus PW. The operative correction of metatarsus varus primus in hallux valgus. Surg Gynecol Obstet.1934; 58:183–191.
3.     Catanzariti AR, Mendicino RW, Lee MS, Gallina MR. The modified Lapidus arthrodesis: A retrospective analysis. J Foot Ankle Surg. 1999; 38(5):322-332.
4.     Roukis TS, Landsman AS. Hypermobility of the first ray: A critical review of the literature. J Foot Ankle Surg. 2003; 42(6):377-390.
5.     Roling BA, Christensen JC, Johnson CH. Biomechanics of the first ray. Part IV: The effect of selected medial column arthrodeses. A three-dimensional kinematic analysis in a cadaver model. J Foot Ankle Surg. 2002; 41(5):278-285.
6.     Ray RG, Ching RP, Christensen JC, Hansen ST. Biomechanical analysis of the first metatarsocuneiform arthrodesis. J Foot Ankle Surg. 1998; 37(5):377-385.
7.     Sangeorzan BJ, Hansen ST. Modified Lapidus procedure for hallux valgus. Foot Ankle. 1989; 9(6):262-266.
8.     Langan TM, Greschner JM, Brandão RA, Goss DA Jr, Smith CN, Hyer CF. Maintenance of correction of the modified Lapidus procedure with a first metatarsal to intermediate cuneiform cross-screw technique. Foot Ankle Int. 2020; 41(4):428-36.
9.     Abben KW, Sakow CF, Sorensen T, Chang HC, Boffeli TJ. First tarsometatarsal joint fusion for hallux valgus deformity: a retrospective comparison of two fixation constructs regarding initial maintenance of correction and complications: traditional crossing screw fixation versus dorsomedial locking plate and intercuneiform compression screw. J Foot Ankle Surg. 2022; 62(2):347-54.
10.    Manoli A 2nd, Hansen ST Jr. Screw hole preparation in foot surgery. Foot Ankle. 1990 Oct;11(2):105-6.
11    DiDomenico LA, Fahim R, Rollandini J, Thomas ZM. Correction of frontal plane rotation of sesamoid apparatus during the Lapidus procedure: a novel approach. J Foot Ankle Surg. 2014 Mar-Apr;53(2):248-51.
12. Feilmeier M, Dayton P, Kauwe M, Cifaldi A, Roberts B, Johnk H, Reimer R. Comparison of transverse and coronal plane stability at the first tarsal-metatarsal joint with multiple screw orientations. Foot Ankle Spec. 2017;10:04–108.
13. Jones JM, Schleunes SD, Vacketta VG, Philp FH, Hentges MJ, McMillen RL, Saltrick KR, Catanzariti AR. First tarsometatarsal joint arthrodesis for hallux valgus with and without intermetatarsal screw fixation: a comparison of correction and maintenance of correction. J Foot Ankle Surg. 2022 Feb 28; S1067-2516(22)00058-8.
14.     Sangeorzan BJ, Hansen ST Jr. Modified Lapidus procedure for hallux valgus. Foot Ankle. 1989 Jun;9(6):262-6.
15.    DiDomenico LA, Spingola HD, Butto DN, Matta M, Moore N, Khan M. Retrospective analysis of intermetatarsal screw failure in a modified Lapidus arthrodesis technique. Presented at the American College of Foot and Ankle Surgeons Annual Scientific Conference, 2023.